Selective signaling system



April 1, 1947. F. H. HANLEY `SELECTIVE SIGNALING SYSTEM Filedl Aug. 12,1943 A TTORNE Y Patented Apr. 1, 1947 SELECTIVE SlIGNALING SYSTEM FrankHarold Hanley, Butler, N. J., assigner 4to American Telephone andTelegraph Company, a corporation of New York Application August 12,1943, Serial No.498,268

Thislinvention relates tosignaling systems and, more particularly, toapparatus for transmitting xsignalsbetween two or morestations'so'thatthe y'signals `may .be `rendered'visible at thestations. Still more particularly, this inventionrelates toapparatus"fortransmitting groups of pulses from .one station to one ormore other -`stations in accordance with predetermined `signals orcharacters, the apparatus including means at the receiving station orstations for converting the variousgroups of fpulses corresponding tothe signals or characters into visual signals or characters so that theymay be observed and read at the receiving `station or stations.

'Divisional application Serial N o. 545,864, dated July 20, 1944,directed to matter disclosed but not claimed in this application hasbeen'filed.

There are diiierent types of equipment avail able "for handlingcommunications between telephone or telegraph offices. These includemanual telegraphsystems, teletypewriter systems and ftelephone systems.Manual telegraph systems usually contain simple parts and are thereforefless costly than the other systems for simple `routine communications.Hence such lsystems are used more vfrequently than the others. VTele-Stypewriter systems -embody more expensive apparatus, and it is oftenimpractical to employ "such apparatus at lplaces'where communicationlfacilities are required. However, the use of man- -ual telegraphsystems for interoffice Vcommunicationhas fallen oiirecently because ofthe short- 4age of Morse operators, and because of the length 'of timerequired to train operators inthe tech- Anique ofsending andreceivingMorse code signals. t

Accordingly it isfan object of this invention to provide simple and:economical communication apparatus which will Inot `reduire Morseoperators .or other skilled personnel. The Varrangement `of thisinvention .in general consistsof a transmitter having a'start-stopdistributor con- V trolledby aplurality of non-locking'push but- `tonkeys Aarrangedsothat the operation oi any key Vmay produce two (or more)pulses, 'for example, a spacing pulse followed by a Vmarking pulse, fortransmitting a ,predetermined character or signal to a distant receivingpoint. The receiving apparatusinvolved in theinvention. may includeastart-stop distributor, a scanning disk havingtransparent charactersand a neon tube associated `witlrthe ldistributor and the Ascanning-disk -or lfurnishing illumination for the characters'tobe illuminatedat the-receiving'station. "The receivingapparatus is arranged to respond`8 Claims. (01.177-353 to the `groups of pulses received and illuminatethe character tor signal defined by the pulses. The system differs fromthe usual teletypewrit'er fsystemin that simpler codes are usedto conveythe `signals or characters and, `moreover,:the :signals 'or charactersreproduced bythe receiving apparatus are not recorded but are madevisible for a brief interval ottime. The receiving :attendant willobserve each character illuminated by the neon tube, and as the desiredYcharacter appears before the scanning disk, itwill ibe'the only oneilluminated atthe receiving point.

in the apparatus used to carry out th'einvention about half ci thecharacters may-be'transmitted by means of codes or signals having ibuttwo `pulses which will lbe referred to as twotransition codes. The rstpulseof a two-'transition code will be a spacing pulse, and it -will 'befollowed by a marking pulse. The overall length `of the twopulsesforming the code may'beconstant, but therelative lengths of themarkingand spacing pulses will dier from eachother vfor the differentcharacters. The other half of the characters may be transmitted by meansof -codes Ehaving four pulses which will be referred Y-to asfour-transition codes. The pulses forming the characters transmitted byfour-transtion codes include a spacing pulse, a marking pulse, a secondspacing pulse and a second marking pulse. The first two pulses of thefour-transition codes are short pulses of equal duration but the secondspacing lpulse generally will be of a different length from the secondmarking pulse. The re1- ative lengths of the second spacing -andmarkingpulses will be different fromeach other "for the different characterstransmitted by four-transi- `tion codes.

When considered from a diierent point of View, the transmittingapparatus may -be thought of as producing different groups of pulsesforthe different characters to be transmitted. For Athe two-transitiontypes of codes, the two pulses deiining each character are of relativelydifferent lengths, although the overall lengths of thepulses of thevarious groups are the same. Thereceiving apparatus includes a rotary'device having the various characters displayed along its periphery atdifferent peripheral distances from a iixed or predetermined point. Eachcharacter may be looked .upon as dividing the Vcircumference oftherotary device into 'two parts, which are proportional tothe lengthsof the two pulses dening that character. The reception of the firstpulses will start the rotary device in lrota- 'tionpast the `xed lor`predetern'lined 'point 4'and .pressionofitheikey Q fo'f Fig. il-Ethe.contact YQ fis opened .to .interrupt the :flow :of .current overdine'LL .and thatasithe brush .Y'BI :contacts the segment YQI, .battery:Buis connectedto'thefline LL ',andremains .connectedto the fline LL toallow `.asulostantial flow 'of .current there-over. The interruptionofthe flowof Acurrentfover line'LL produces a spacing pulse, and'thelsubsequent closure of the line LL produces 1a marking pulse. The

spacing pulselasts foriahout `two units ottime, for f "example, .whilethe 'corresponding marking pulse lasts .for at least eighteen units oftime. Thusk the Yletter orcharacter'Q may loe `conveyed to the=dis :tantstation B'bymeansoiaztwo-transition code, ,as already referred to.Whenzthekey W Yof Eig. l

.is depressed 'by the operatorgthe contact YW will be opened instead .ofthe contact YQ, and thence "a two-transition :code consisting of a"spacing,

'pulseof about three iunitsanda vcorresponding marking pulse of iatleast :seventeen units'will loe transmitted over ftheiline LLtotheapparatusat statici-1B. ,The character Emay likewise bacionveyed tothedistant tstationB by :a'spacing pulse of four units andacorrespondingfmarking pulse :offat least sixteen units,:tand-so on.lEach oiathese` ,it has .completed ,one revolution. It is ialsonotedthat `the relay SRwill Abereleased `onlyias, long as one of `the keys.of the keyboard remains despressed. `As soon as the key i's'rele'ased,the Winding fof `relay'Slft will becomezre-,energizedfisc .as to causeits armature to closeiitsicontactM. The

voperationzof relay SRwillzremoVe the resistorRi from the circuitYsothat the sending "apparatus 'will be ready vfor the transmission loflanother .'c'haracter.

The .relay SR is `adjusted 4'so as to loe 'slightly slower '.to releasethan magnet YM, thefrelease of the relay "being completed ibefore :brushYBI leaves segment YST. -Conseduently, upon the depresson'of one-of thekeys o-ffthe keyhoardfsuch .as key A, the series circuit including thewindings ofrelay `SR and magnet YM will be opened,

allowing the brush arm .YBA to start to `rotate zjust :beforethearmature'of relay SR releases .to close its back contact S. Upon theclosure of .contact Sby the armature of slow-release relay SR, batteryB1 will be connected through resistor R1 to the continuous. segment YSS.Hence, when brush YBI reaches-thesegment YAZ, current will againtraverse the winding of magnet YlYLas already explained. This circuitmaybe traced from battery B1, the armature and contactS of `,relay SR,resistor R1, `continuous 'segment YSS, brushes YBl .of brush arm YBA,`segment YAZ, contacts YS, YX, YD, YC YK, YL, magnet YM, and AlineLL tostation .B and battery B2. .This circuit will cause magnet YM to become11e-.energized to attract .its latch so as to prevent the brush farmYBAfrom rotating more thanl onerevolution even if the` attendantholdsthekey A depressed longer than is required for-the brush arm YBAto complete'its revolution. Relay-'SR will becomereop- :erated after the previouslydepressed key @A .has

key, the;pulses1corresponding `to the fsame charactel` "or #any bother.characterrnay be transmitted bydepressing the Aappropriate `key .of the`key flooard.

Arly one of contacts YQ, YW, YE, YR, YT `which areshown on the inner,peripheryiof the sending unit YSU maybe opened `loy thecorrespondingkeyof the keyboard offFig.1nfor sending a `two-:transition-code overline fLL tothe receiving station B. The remaining contacts YI, Y2, Y3,Y6, YS YL shown on the outer periphery of the `sending unit YSU are`controlled `hy other keysof the keyboard of Fig. 1. When the key "i ofFig. l is depressed, ythe swinger lof thefcontact Yi will bemovedupwardly to close theupper contact (whichis normally open) fortransmitting coded impulses over thelineLL. As the vcontact YI becomesso operated, it will open thecircuit of the-line LL extending tostationB, this circuithaving .beenzpreviously described with Yrespect to thetransmission of thecharacteriQto .the .distant station B. As themagnet'YMbecomes released, the brush-arm YBA will -again rotate'inaclockwisedirection in the same manner as already describedheretofore..As the brush YBlpa-sses over segment YST, the line .LL will beopenedinthe samernanner as the line LL was initially opened when thekey Q wasoperated.

When the brush YB! :contacts :segment YSI-I, battery B1 will yhe,connected to line LL and station B overa circuit :which includes, inaddition .to battery B1, `the armature and back contact S of relay SR,resistor R1, the continuous segment `YSS, brush YBI, segment YSH, the.contacts of Yi, .contacts YW, Y2, YE, Y-3, YR, .YA YK, YL, magnet YM,line-LL and station` B. rhis will close line LL and theline -will remainclosed during the remainder of the travel of brush arm YBA throughoutits revolution. Thus theoperation of key I will produce a spacing pulsefollowed by a marking pulse, these pulses resembling the vpulsesproduced byfoper- `ating .key Q, but it will vbe shown hereinafter `thatthe `character l will be exhibited at thereceiving station B.

When key 2 .oi Fig. -l is closed, the swinger .of .contact Y2 willbemoved upwardly to Vclose its upper terminal `(which is normally open)..This will-cause `relay SR and magnet YM to release, asalreadydescribed. The release of magnet YM .will .againpermit thebrush arm YBAto rotate' as before, .As brush YBI contacts segment Y ST, `the line LLwill Yhelopened by the disconnection of battery B1 from line LL. Thiswill result in ra spacing pulse. Battery B1 will be connected to ,lineLL.when brush YBI contacts segment YSH,

the'circuitto .line LL being completed through segment YSH, contactY2,.contacts YE, YS, YR, Yll YL and the winding of magnet YM. This willresultin .a markingpulse. When brush .YBA contacts .segment YQI, .theAbattery YB1 will `again he disconnected .fromlineLLat the contacts Y2andhence there will be another spacing pulse. When brushYBl thencontactssegments YW2, `the .battery .Bi will again be connected to lineLL, Ythe `circuit being completed through segment .Y W2, contacts YE,YS, YR,Y4, YT, .Y YK, YL, magnet YM, and line LL. This will produce -asecond `marking pulse. The

circuit to line ,LL will remain closed during the .remainder of thetravel of .brush .YBl .through its cycle. Thus the operation of :key 2will result .in `.four pulses, i. e., spacing, marking, .spacing i andmarking pulses, the rst three of the pulses being substantially equalunit pulses while the fourth (marking) pulse will be about sixteen unitslong. Other keys associated with the contacts of the outer peripherywill cause the production of two unit pulses (spacing and markingpulses) followed by two longer pulses of relatively different lengths.

At station B (Fig. 3) the various groups of pulses .received operate therelay RR and cause its armature to follow these pulses. The armature ofthe relay RR will close its contact S when a spacing pulse is receivedand its contact M when a marking pulse is received. The segments ZQI,ZW2, ZES, ZRA, ZT5, ZYB ZKL, although positioned concentrically aboutthe axis of the brush arm ZBA and separated from each other, arenevertheless conductively connected to each other by a conductor ZKDi.As the first or spacing pulse corresponding to the letter AQ is receivedand the armature of relay RR closes its contact S,the absence of currentin the magnet ZM (due to the opening of the circuit of the line LL) willunlatch the brush arm ZBA to enable it to rotate in a clockwisedirection. As the brush ZB2 contacts segment ZST-Which is a shortsegment and is contacted at about the time when the brush YBA at thetransmitter is half way across segment YST-the condenser C Will becomecharged to the positive voltage ofbattery B3. The charging circuit forcondenser C includes battery B3, resistor R3, segment ZST,

i brush ZB2, the continuous segment ZSS, and conductor ZKDs which isconnected to the lower terminal of condenser C, the upper terminal ofthe condenser C being connected to ground hrough the armature andcontact S of relay RR. The battery B3 will be disconnected from the vcondenser C immediately after the brush ZB2 leaves the segment ZST, butthe positive potential applied to the condenser C will remainsubstantially unchanged. As the brush ZB2 next contacts the segmentZSH-which is positioned so that its contact with the brush ZB2 willo-ccur at about the time when the brush YBI at station A is half-wayacross the segment YSH- the negative battery B4 will then be connectedto the condenser C. The circuit to condenser C now includes battery B4,resistor R2, segment ZSH,

brush ZB2, continuous segment ZSS, and conductor ZKDs connected to thelower terminal of condenser C, the upper terminal of which is stillconnected to ground through the armature and contact S of relay RR. Asthe latter circuit interconnecting battery B4 to condenser C iscompleted, the condenser C will first discharge and ,then charge to theopposite or negative potential of battery B4. When the brush arm YBA atthe transmitter reaches the segment YQI, current will again flow overthe line LL and through the upper winding of relay RR as alreadydescribed hereinabove, thereby causing the armature of relay RR to closeits contact M. At the same time the magnet ZM will be re-energized so asto lower its latch to its normal position to prevent any furthermovement of the brush arm ZBA after it has completed a revolution. Butit is noted that the brush YB! at the transmitter of Fig. 2- is midwaythrough its segment YQ at the time when brush ZB2 of Fig. 3 contactssegment ZQI. At that time conductor ZKDi will beeiectively connected `tothe conductor ZKD3 through the continuous segment ZSS. Consequently theresistor R5 will be bridged across the condenser C, the bridging circuitincluding the armature and contact M of relay RR, the resistor R5,conductors ZKDz and ZKD1, brush ZB2, continuous segment ZSS andconductor ZKD3.

It is noted also that the two electrodes .of the neon tube ZT arebridged across the resistor Rs. ThusV both the tube ZT and the resistorR5 are shunted across the condenser C at about the time when the brushZB2 contacts the segment ZQi. The condenser C is, therefore, dischargedat a very rapid rate. In discharging the upper or positive terminal ofthe condenser will be connected to the upper terminal or electrode ofthe tube ZT, while the lower or negative terminal of the condenser Cwill be connected to the lower terminal or electrode of the tube ZT. Theapplication of a voltage of such polarity to the electrodes of thetubeZT will cause the upper electrode of the tube ZT to become luminous,and the luminosity will remain substantially the same until the voltageon the condenser C is reduced below the voltage required to sustainionization within the tube ZT. The time during which the upper electrodeof tube ZT remains luminous depends on the constants of the dischargecircuit and tube ZT.

It will be remembered that the scanning disk SD is fixed to the brusharm ZBA so that both rotate together about their common axis. Itfollows, therefore, that when the brush arm ZBA contacts the segment;ZQI, the letter Q of the scanning disk SDv will then be positionedimmediately in front of the upper electro-de of the tube ZT which hasjust become luminous. Therefore, the letter Q will become visible to theattendant. The letter Q may be, for example, transparent so that thelight emanating from the upper electrode of tube ZT will freely traversethe transparent contour of the letter. The letter Q will, therefore, bevisible for a brief but appreciable period of time, an interval longenough to enable the attendant to observe it. Were the key W of Fig. 1depressed instead of the key Q, the condenser C at the receiver woulddischarge at about the time when the brush ZB2 contacted the segmentZW2. In this case, of course, the letter W of the scanning disk SD wouldbe positioned adjacent to the upper electrode of the tube ZT at the timewhen the upper electrode of tube ZT became luminous and then letter Wwould be visible to the attendant. And so on for each of the other twotransition codes transmitted from station A of Fig, 2 to station B ofFig. 3 to convey other characters such as E, R, T, etc. to the distantstation B.

When the pulses corresponding to the character No. 1 are received atstation B, the first spacing pulse (of unit length) will release themagnet ZM of Fig. 3, thereby permitting the brush arm ZBA to rotateclockwise. When the brush ZB2 contacts segment ZST, the positivepotential of battery B3 will be applied to the lowerterminal ofcondenser C over the same circuit previously described with regard tothe response to the rst spacing pulse of the character Q. Upon thereception of the subsequent marking pulse from station A, relay RR willcause its armature to close its contact M. When brush ZB2 contactssegment ZSH, the negative potential of battery B4 will be connected tothe lower terminal of condenser C, but condenser Cy will not bedissisi-snoei charged at that' time.` ereason for the: positivechargeremaining on condenser C isf that the upper terminal of thecondenser is not con-v nectedto ground through the armature and contactS of relay RR and hence there is no complete discharge path for thecondenser.

When the brush ZBZ thereafter contactsfseg-` however, the lower plate oftube ZT will receiver thev positive potential previously applied to the'lower plate of condenser C,ithereby causing the lower plate of tube ZTto become illuminated. The character l of the scanning disk SD will bepositioned in front of the lower plate of tube ZT just when it isilluminated so that the character l will become visible to theattendant.

When the pulses corresponding to the character 2 are received fromstation A, the rst unit spacing pulse moves the armature oi relay RR- toits contact S. As brush ZB2 contacts segment ZST, the condenser Cbecomes charged by battery Ba to render the lower plate of condenser i Cpositive withrespect to its upper plate, as a1- ready explainedhereinabove. The rst unit marking pulse received from station A willthen move the armature of relay RR to its marking contact M. Hence whenbrush ZB2 contacts segment ZSH, the positive charge on the lower plateof condenser C will remain undisturbed, as explained hereinabove inregard to the reception of the marking pulse of character No. l atthetime when brush ZB2 contacts segment ZSH. When the second unit spacingpulse is received, the armature of relay RR will return to its spacingcontact S and hence when brush ZB2 contacts segment ZQI, the charge oncondenser C will remain substantially unaffected. This is because theconnection of conductors ZKD1, ZKDz and ZKDs to each other by brush ZBZand segments ZQl and ZSS will not discharge the condenser C when thearmature of relay RR is removed from its contact M. However, when thesecond marking pulse is received it will move the armature of relay RRto its contact M. Hence when brush ZBZ contacts segment ZWZ, thedischarge path for condenser C will be completed. Condenser C will thendischarge through resistor R5 and tube ZT and will illuminate the lowerplate of tube ZT because it has then been` rendered sucientlypositivewith respect to its upper plate. The illumination of the lower plate oftube ZT will occur at about the time when character 2 of the scanningdisk SD is oppositeY the illuminated plate. This character willtherefore become visible to the attendant.` The illu-- mination of tubeZT will cease `immediately after the condensers voltageY is dischargedbelow the ionization point of the tube even though the chari acter 2 hasnot passed tube ZT.

Similarly the reception of pulses corresponding to othercharacters suchas 3, 4, etc., will illuminate the tube ZT at about the time when thesecond marking pulse is received. Thus in all cases of two-transitioncharacters, the second marking pulse-will initiate the discharge ofcondenser C for a-brief, but appreciable time interval" and illuminatethe lower plate oi tube ZT at about the'l time when thef particularcharacter"- ofi the' scanning disk SD reaches tne tube ZT. The tube ZTis stationary. Itsposition marks a point which i's-'spacedifrom thevarious characters ci disk SD by peripheral distances which correspondto the interval preceding the finalmarking pulsey re.- ceived:

Iidesired Vail ofthe characterson disk SD mayl be spaced-from each otheratshorter intervalsso that they may all be conveyed from stationAtostation Beither by two-transition pulses or byfour-transition pulses.

simplerV and more easily constructed.

tis importanttoI hold any one of the keys (ii-Eig. l, suchas key E;depressed-until the brushy arm passes the segment YESfwhich is connectedto contact YE controlled by key lil.` This will prevent lerrorsinsignaling. If this precautonis observed, the' apparatus will operatesatisfactorily.

nsteadof` a device for thetransient illumination of thereceivedcharacter, the receiver maiT ihcludea printing relay or magnetfor printinglr The winding of the' the characters on a tape.printingirelay or magnet would then be energized by the condenserdischarge current.

relay or magnet. Thetape may be controlled for step-by-stepvaction by arelay having its winding in series with-theresistance R3;

Instead oa device for the transient illuminationv of the receivedcharacters, the receiver` mayV in-r clude-af unit for recording-thereceived characters In this ease the diskI withA transparent characters`would berotated` between the'neon'tube and a photographic'lm or paper,

(notsho'wn) all enclosed'in-a darki chamber. The v lrn or tape maybecontrolled for step-by-step -actionby a relay havingitswinding inseries with The light emanating from the tube, thus providing aphotographic record* ofthe received characters.

Although the invention has been described as enabling an operator tosignal `fromV station A to station-Bythe arrangement is suitable fortwoway signaling between' stations A and B (andany other stations).

While this invention has been shown and described in` certain particularembodiments merely for illustrative purposes, the invention is" equallyapplicable to other and widely varied organizations without departingfrom the spirit of `the invention and the scope of the appended claims'.

What is claimed is:

1. A signaling system comprising means forl producing pairs of pulsestherelative time lengths with the characters to be transmitted, althoughthe overall time length of eachpair of pulses remains the same, a rotarydevice bearing the various charactersalong its periphery at differentperipheral distances from a predeterminedpoint,V a condenser, a gastube, means respo'nsive to theV iirst or the pulses ofeach pair to startsaid rtary device andftochargefsaid condenserfand means responsiveto-/the secondof` the pulses` of` each" pair to discharge saidIcondenser through said` tube to illuminate the character upon the perl-If only' one type of' -pulse is used, the apparatus will be somewhatThis relay* or magnet might serve to press the tape againstl thedi'slcSD to print the character adjacent to the.

l l phery of said device as it passes a predetermined point.

2. Receiving apparatus for reproducing characters transmitted by pairsof pulses of relatively different time lengths, although the overalltime lengths of the different pairs of pulses are the same, comprising arotary disk having the diierent characters exhibited along itsperiphery,each character appearing at different peripheral distances from apredetermined point about said disk, acondenser, a light-producingdevice, means responsive to the iirst pulse of each pair received torotate said disk and to charge said condenser, and means responsive tothe second received pulse of each pair to discharge said condenserthrough saidlight-producing device to illuminate said predeterminedpoint so as to exhibit the character defined by the received pulses.

The combination of means for producing pairs-of pulses, each pair ofpulses derning a different` character, the relative lengths of time ofsaid'pulses differing from each other although theoverall lengths oftime of the various pairs of pulses are the same and are equal to apredetermined time interval, a rotary device bearing the differentcharacters along its periphery at diierent periphreral distances from apredetermined point, said rotary device including a plurality ofsegments each corresponding to a dierent character, said segments beingpositioned concentrically about the axis of said rotary device, acondenser, means responsive to the rst of the pulses of' each pair tostart said rotary device and to charge said condenser, an illuminatingelement, meansy responsive to the second of the pulses of each pair todischarge said condenser through one of said segments to operate saidilluminating element thereby to illuminate the periphery of said rotarydevice as it passes said predetermined point,V whereupon the charactercorresponding to the received pulses will be exhibited.

` 4.' Receiving apparatus for responding to pulses of different lengthsof time, each pulse corresponding to` adifferent character, comprising arotary device upon the periphery'of which are exhibited the charactersto be conveyed by said pulses, said rotary device including a pluralityof segments which are positioned concentrically about the axisof saidrotary device, each segment corresponding to but one of said characters,a

condenser, means responsive to the receipt of each` of said pulses tostart said rotary device in rotation from a predetermine-d pointand tocharge said condenser, an illuminating device, means responsive to thetermination of each of said pulses to discharge said condenser so as toproduce a surge of current through one of said segments to operate thesaid illuminating device as it passes said predetermined point andilluminate the character appearing at the periphery of said rotarydevice as the latter passes said predetermined point.

The combination of means for producing pairs of pulses in accordancewith diierent characters to be transmitted, the relativeV time lengthsof the pulses ofV each pair differing from each other although theoverall time length of the two pulses of each pair remains the same, avcondenser, a gas tube, a rotary device upon which are exhibited thedifferent characters at different vperipheral distances from apredetermined point, said rotary device having a plurality of segmentspositioned concentrically about the axis of said rotary device, eachsegment corresponding to a 12 different character, means responsive tothe iirst of the pulses of each pair to start saidrotary device and tocharge said condenser, means initiated by the second of the pulses ofeach pair todischarge said condenser so as to produce a surge of currentthrough Vone of said segments toionize the gas of said tube andilluminate the character corresponding to the received pulses;

l6. VReceiving apparatus for reproducing characters transmitted by pairsof pulses of relatively different time lengths although the overall timelengths of all of said'pairs of pulses are the same, comprising a rotarydisk having the different characters exhibited along its periphery, eachcharacter occurring at different predetermined peripheral distances froma predetermined point about said disk, said disk having a plurality ofsegments at corresponding peripheral distances from anotherVpredetermined point on said disk, a condenser, means responsive to thefirst pulse of each pair received to rotate said disk and to charge saidcondenser, an illuminating element, and means responsive to theinitiation of the second received pulse of each pair to discharge saidcondenser through one of said segments to operate said illuminatingelement and thereby illuminate the character defined by said receivedpulses.

7. The combination Vof means for producing pairs, of pulses inaccordance with characters to `be transmitted, the two pulses of eachgroup being ofV relatively different time lengths although the overalltime length of both pulses of each pair axis of said rotary device, onesegment corresponding to each different character, a condenser,

a light-producing device, means controlled by the receive-d pulses forcharging said condenser and then discharging saidcondenser through oneof said segments to illuminate said light-producing device, therebyilluminating the character corresponding to the received pulses as saidrotary vdevice reaches said predetermined point in its rotation.

8. The combination of means for producing groups of two pulses ofrelatively different time lengths corresponding to characters to betransmitted, the overall additive time lengths of the different groupsof pulses being the same, a rotary device having said characterspositioned along its periphery so that each character'appears at a pointwhich'divides the circumference ofsaid rotary device into two partscorresponding to the relative lengths of the two pulses of each group,said rotary device including a plurality of segments positionedconcentrically about the axis of said rotary device, each segmentcorresponding condenser, means reto one ofthe characters, a sponsive tothe first p ulse of each received group of pulses to rotate said rotarydevice throughone revolution and to charge said condenser, alightproducing element, and means initiated by the second pulse of eachgroup to discharge said condenser through one of the segments of saidrotary device to illuminate said light-producing element, theillumination being directed at a point,V l inthe path Vof the rotarydevice atwhich appears the character corresponding to the received groupNumber Name Date of pulses. 2,127,005 Nichols Aug. 16, 1938 FRANK HAROLDHANLEY. 2,116,649 Watson May 1|0, 1938 2,104,544 Lemmon Jan. 4, 1938REFERENCES CITED 5 1,620,987 Trenor Mar. 1&5, 1927 2,222,218 WallaceNov. 19, 1940 The fo11ow1ng references are of record m the 2,074,037Watson Man 16, 1937 flle 0f *1111s Patenti 2,120,971 Bailey June 21,193s TEN 1,920,788 Hausrath Aug. 1, 1933 UNITED STATES PA TS 102,138,668 Stewart Nov. 29, 1938 Number Name Date 1,933,650 Bascom Nov."7, 1933 1,933,088 Battegay Oct. 31, 1933 2,082,575 Harrison June 1,1937 2,168,460 Watson Aug. 8, 1939 2,321,605 Kenath June 15, 19432,006,737 Gessford July 2, 1935 2,346,251 Bryce Apr. 11, 1944

